Agilent Technologies 6850 Series II User Information page 146

6.
7.
8.
9.
10. Set the inlet pressure to 25 psi. Wait a moment for the pressure to
11. Turn the pressure off. Because the column and septum purge vent are
12. Monitor the pressure for 10 minutes.
13. When the system is leak free, restore the GC to your normal operating con-
Released: March 2004
Cap the septum purge fitting with a 1/8-inch Swagelok cap or with a capil-
lary column nut, a solid piece of wire (such as a metal paper clip), and a
0.5 mm id graphite ferrule.
Septum purge vent
Make sure that the pressure at the gas supply is at least 35 psi. Carrier
source pressure should always be at least 10 psi greater than the desired
inlet pressure.
Use a Control Module or ChemStation/Cerity Chemical to define a capil-
lary column. Enter a length of 0 m and any diameter. The inlet will now be
in pressure control mode.
Set the inlet and oven to normal operating temperature.
equilibrate. The pressure may exceed the setpoint briefly while it equili-
brates.
If the pressure cannot be reached, either there is a gross leak in the system
or the source pressure is not high enough.
capped, the pressure should remain fairly constant.
• If there is a pressure loss of less than 0.7 psi (0.07 psi/min or less),
consider the system leak tight
• If the pressure drop is much greater than 0.7 psi, there is a leak that
must be found and corrected. See
ditions. Remove the cap from the septum purge, install the column,
define/undefine the correct column, and restore operating temperatures
and pressures.
6850 Series II GC User Information
Routine Maintenance: Inlets
Maintaining a purged packed inlet
"Correcting leaks" on page 147.
page 146 of 256